Method of and apparatus for indicating the size of the particles in ore pulp flowing in conduits



Jan. 8, 1929. 1,697,867

\ H. E. T. HAULTAIN METHOD OF AND APPARATUS FOR INDICATING THE SIZE OF THE PARTICLES IN ORE PULP FLOWING'IN CONDUITS Filed Sept. 12. 1922 INVENTEIR Ream \ I AT M' Patented Jan. 8, 1929.

UNITED STATES PATENT OFFICE.

HERBERT E. T. HAULTAIN, OF TORONTO, ONTARIO, CANADA.

METHOD OF AND APPARATUS FOR INDIOATIIN'G THE SIZE OF THE PARTICLES IN ORE PULP FLOWIN'G IN" CONDUITS.

Application filed September 12, 1922. Serial no. 587,763.

It is desirable for. certain purposes to be able to determine approximately the average size of the particles in an ore pulp flowing in a closed circuit or passing, from one apparatus to another, and m o ject is to devise a process of and automat1c apparatus for givingcontinuous indications of the changes which may occur in the average size of the ore particles in pulp, and which will, if desired, record such changes.

I attain my object by constantly-and regularlywithdrawing the flowing pulp or a small proportion of the pulp and effecting a concentration or a separation more or less .complete of the coarser particles therein in a downwardly and upwardly extending tube in such a way that the apparent specific gravity of the contents of the tube or a stratum thereof may be taken or constantly indicated by suitab e apparatus- The apparatus used is illustrated in the accompanying drawings in which Fig. 1 is a vertical section of one form of the apparatus;

Fig. 2 a similar view showing the specific gravity indcating apparatus; and

. Fig. 3 a similar view of a further modification. i

In the drawings like numerals of reference indicate corresponding parts in the difierent figures.

1 represents a launder or other conduit through which an ore pulp is flowing. Extending down from this launder is asubstantially vertical pipe or conduit 2 having a valve controlled opening 3 at its lower end. A lateral outlet 4 communicates with a vertical conduit 5 which is preferably-adapted to.

discharge into the launder and is prov1ded at its lower end with the valve controlled hydraulic jet 6. v

Ore pulps usually contain particles of d1f-' ferent sizes. In certain metallurgical operations it is necessary that -the average size of the ore particles shall not vary very greatly from a predetermined standard. It 1s important therefore to know at any time 1f and to what extent any variation has taken place. It is further found that if there is an increase in the average size of the partlcles that there is a proportional increase in the size of all the particles in the ore. Therefore, if the larger partx-fes n;- separated out from the ti'cles andtherefore of the average size 0 pass into it, by

smaller particles a change in their size will be a substantially accurate indication of the change in the average size of the particles of the ore.

If now, in the apparatus illustrated in Fig. 1, an upward flow be created in the condu1t 2 b admitting water through the valve-contro led opening 3, the rate of travel of the water being predetermined and definite, but less thanthe falling rate of-the larger particles which settle down through it,it is found that the finer constituents of the pulp do not pass down into the conduit at all, or to but a small extent, in the main passing up with the water, and that the conduit contains a pulp including only the larger constituents conditions, that any change in the size of' the larger particles in the ore pulp in the launder results in corresponding changes in the specific gravity of the pulp in the conduit 2 so that by measuring the specific gravity of this column or a predetermined stratum thereof indications may be obtained of changes inthe average size of the larger fparthe garti'cles in the pulp flowing in the laun- To make the apparatus continuously operating, it is necessary to constantl remove pulp from the conduit 2 and thus 0 ange its contents so that'at any given time they represent a fair sample of the larger ore particles in the pulp flowing in the launder. For this pu ose water is admitted to the valve contro ed hydraulic jet 6 which creates an upward current in the conduit 5 which will carry upward the heavier ore particles which the conduit 2.

The ap aratus' for indicatin the specific gravity 0 the pulp in thecon uit 2 may be of any known form, but is preferabl as illustrated, comprising aninverted -tube 10, the legs of which are connected to the conduit 2 at different levels. The legs of the U- tube are filled with water or other liquid and the bend with a diiferentliquid.;This apparatus will indicate the mean specific gravity .of the stratum of ulp between the points of communication 0 the legs with the conduit and any change is readil noted.

It will beseen'thatthe princip e of opera-- gravity from the bottom of v tion of the apparatus is that the pulp sample is acted on by gravity against an upward flow of liquid.

The same principle of operation is embodied in the construction shown in Fig. 2, in which a conduit 7 is shown as connected with the launder, which conduit is connected by means of U-tube 8, preferably of smaller diameter, with an upwardly extending conduit 9. The pulp drawn from the launder through the conduit 7 rises through the conduit 9, where it is subjected to the influence of gravity acting against the flow, and flows out of the top of theconduit. The result is that there is more or less of a concentration of the larger particles'at any time, as the smaller particles rise more rapidly. A measurement of the specific gravity of a stratum of the column of pulp in this conduit will therefore give an indication of the size of the particles therein as in the case of the construction shown in Fig. 1 as long as the liquid-.-

solid ratio of the pulp remains fairly .constant.

In Fig. 1 the heavier ore particles are ier ore particles. The heavier particles tend to fall faster in the conduit 7 than the lighter particles and to rise more slowly in the conduit 9. Consequently there is separating out of the heavier particles at the bottoms of these conduits. After a certain condensation has been reached, the heavier particles pass away through the upper end of the conduit 9 at a rate substantially proportionateto quantitative ratios between the light and heavy particles.

The preferred arrangement, however, is to obtain an indication of the difference of the specific gravity of a stratum of the pulp in the conduit 7 and a stratum of the pulp in the conduit 9, as in that case the effect of differences in the liquid-solid ratio is substantially The difference in the specific gravity between the two legs may be indicated and recordedvin the following manner. 'A movable me ber 12 is provided and means are provi ed whereby the pressures existing in the long leg of one U tube and the short leg of the other U tube act on this member in one direction and the pressure existing in the a chamber 13 and these chambers are pro vided With'flexible diaphragms 14 of known type. The diaphragms of the chambers connected with the longer legs of the U tubes are shown as facing in opposite directions and are connected respectively with the arms 15 and 16 formed on the movable member 12. The diaphragms of the shorter legs of the U-tubes face one another and engage the arm 17 on the member 12, all the diaphragms acting lengthwise of the movable member 12. 'This member may be connected by a link 18 with a stylus 19 fulcrumed at 20 on a suitable stationary part. This stylus may be used to record movements of the movable member 12 on a movable web of paper as is common with recording measuring instruments.

It should be borne in mindthat pressure to operate the part 12 is obtained by a difference of level between'the liquid in the two legs of one of the U-tubes. The greater the difference in level between the upper ends of the liquid columns the greater the pressure. It will be noted that the difference in level between the upper ends of the liquid columns in the two legs of the U-tube at the right hand of Fig. 2 is considerably greater than the difference in level at the up er ends of the two columns'at the left han side of the figure because the specific gravity near the bottom of the conduit 9 is greater than in the same part of the conduit 7. Consequently there is will be noted that the level in the right hand longer column is higher than that of the left hand longer column. Consequently between these two a balance of pressure exists tendin to move the part 12 to the right. The 1e hand shorter column shows a higher liquid.

level than theright hand shorter column. However, again a balance of pressure exists tending to move the part 12 to the right.

A further modification of the conduits is shown in Fig. 3, the conduit 7 bein shown as inclined so that the heavier partic es tend to settle against the lower side of the tube and thus reduce the specific gravity of the column as a whole. Various modifications of this arrangement are possible.

In Figs. 2 and 3iit'will be noted that all the pulp flow, if it is not too heavy, may pass through the conduits, 7 and 9, though, as a rule, the apparatus will usually be made of small dimensions and a portion only of the pulp flow led through it.

Theapparatus described will'be found to i give very satisfactory results with ore pulps in which the proportions of the fine and coarse ore particles does not vary greatly but only the average size of theparticles, which condition usually obtains in ordinary plants.

What I claim as my invention is 1. A method of determining variations in the average size of the ore particles in an ore pulp flow which consists in continuously separating out the finer particles from said 10 pulp while in motion in a conduit, and determining the variations, if any, in specificgravity of the pulp containing the coarser particles.

2. Themethod of determining variations in the average size of the ore particles in an ore pulp flow which consists in causin a liquid in which the particles are suspen ed to flow continuously in a suitable conduit first downwardly and then upwardly to cause aseparation of the finer and coarser particles and determining the specific gravity of a stratum of both flowing pulp.

, the upflowing and down 3. Apparatus in the average size of the ore particles in a flow of ore pulp comprising a launder for the main pulp flow; a conduit communicating therewith and depending therefrom adapted to draw ofi' a portion of the pulpflow; an up for determining variations wardly extending conduit communicatinfglrat HERBERT E. T. HAULTAIN. 

